Manipulate a Plot of Evaluate DSolve

*To*: mathgroup at smc.vnet.net*Subject*: [mg127492] Manipulate a Plot of Evaluate DSolve*From*: barandiaran.juan at gmail.com*Date*: Sun, 29 Jul 2012 03:05:21 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net

Hi, I'm trying to Manipulate a Plot of a quite difficult function which involves solving a differential equation, but cannot be solved analytically. To try to simplify the example and simulate it, let's assume that we have the following function: func[coef_] = {{y -> Function[{x}, DSolve[y'[x] == Cos[coef *x], y, x]]}} Manipulate[Plot[{{Evaluate[y[x] /. func[coef] /. C[1] -> {Range[-5, 0]}]}}, {x, -10, 10}], {{coef , 1}, 0.1, 5}] I get an error: DSolve::dsvar: "-9.99959 cannot be used as a variable" I think that this is because Manipulate assigns a value to x (= -9.99959) BEFORE solving the DSolve, even though to avoid it I'm using the Evaluate function, which should process the function before assigning a value to x. But the thing is that the "coef" to be Manipulated is at the same "level" as the x in the Manipulate block, so probably if I need the coef to solve the DSolve, I also have the x that gives me an error. Is there any workaround? I guess I'm not understanding properly how Mathematica processes these simple expressions. Thanks, Juan

**Follow-Ups**:**Re: Manipulate a Plot of Evaluate DSolve***From:*John Fultz <jfultz@wolfram.com>

**Re: Manipulate a Plot of Evaluate DSolve***From:*Bob Hanlon <hanlonr357@gmail.com>

**Re: Manipulate a Plot of Evaluate DSolve***From:*Bob Hanlon <hanlonr357@gmail.com>